1. Field of the Invention
The present invention relates generally to equipment for handling intermodal and other transportation containers for transporting materials in bulk, and more particularly to an apparatus configured for attaching to and tipping containers to empty bulk materials from such containers.
2. State of the Art
Intermodal and other transportation containers are often used for transporting various materials in bulk, such as coal, grain, gravel or other materials. One particular application of the use of intermodal containers includes the transportation of waste materials bulk, including various refuse, low level radioactive materials, contaminated soils and the like. Intermodal containers are typically handled by various loading/unloading equipment to transfer the containers between transportation vehicles, such as railroad flat cars, trucks and steamships. For example, a reach stacker may be used to handle and transfer the containers between trucks and railroad flat cars, or to reposition containers in a yard. A reach stacker typically has a telescopic boom to which an expandable attachment (commonly referred to as a “spreader”) is attached. The spreader includes a plurality of ISO twist locks that are configured to engage and attach to the intermodal container for lifting. A hydraulic motor and gear reduction system permit clock-wise and counter-clock-wise attachment rotation. Such spreaders are often provided with side shift, manual pile slope capabilities and adjustable guide arms. In addition, electrical safety sensors prevent the twist locks from being locked or unlocked while the spreader is “unseated” and prevent attachment extension or retraction when the twist locks are “locked” or “seated.” A twist lock safety interlocking system ensures correct locking procedures. Such reach stackers are manufactured and sold by various companies including the Hyster and Taylor companies. In some instances bulk cargo must be transferred from one intermodal container into another container for shipment, processing or storage or otherwise dumped from the intermodal container. For example, contaminated soil may need to be transferred from an intermodal container to a railroad hopper car for shipment to a remote storage facility. As a result there remains a need for an efficient method of emptying intermodal containers and thereby transferring bulk material from the container into another receptacle.
One known apparatus for assisting the removal of bulk material from an intermodal container is disclosed in U.S. Pat. No. 6,966,741 to Gay et al. Gay et al. discloses an apparatus comprised of upper, middle and lower frames in which the middle and lower frames are arranged to pivot with respect to each other about an axis near one end of the frames. A winch motor is positioned on the upper frame and a cable is attached to the lower frame so that the lower frame can pivot away from the upper and middle frames and empty the contents of the intermodal container. The Gay et al. device, however, can result in unstable conditions during operation in the manner in which it lowers one side of an intermodal container relative to the other thus effectively laterally moving the center of gravity of the intermodal container. As such, there is a further need in the art to provide an intermodal container tipping apparatus that maintains lateral stability of the equipment during the tipping operation by maintaining the center of gravity of the intermodal container during a tipping operation and that is easily adaptable to various types of existing lifting equipment, such as side loaders, reach stackers, cranes, etc.